Rotary pump and compressor



A ril 24. 1928."

R3 J. P. E. COZETTE ROTARY PUMP AND COMPRESSOR Filed June 15; 1926 2 Sheets-Sheet 1 R. J. P. aicoz'E'rTE ROTARY PUIP ,Imb' COMPRESSOR April 24, 1928,

' Filed 13141561926 2 Sheets-Sheet 2 of example only, two ways in'whic Patented Apr. 24, 1928.

UNITED STATES RENE JEAN PAUL Em- COZET'I'E, OI NEUILLY-SUKSEINE,

ROTARY PUMP AND COMPRESSOR.

Application filed June 15, 1928.; Serial No. 116,223.

- This invention relates to high speed rotary pumps and compressors. Among the objects of the invention are,

to simpli fy the construction of devices ofthis character,- to cheapen the cost 0 their production, and to increase their fiiciency and life.

Further objects and advantages will appear n the following description of the invention. y

In the accompanying drawings is represented in a-schematicmanner, and b way i: this invention can be carried out;

In the drawings:

Fig. 1 is a transverse sectional view of a usual construction of pump of the kind in uestion.

ig. 2 is a transverse sectional view on line 2-2 of Fig. 3. i

Fig. 3 is a longitudinal sectional view on line 3-3 of Fig. 2.

Fig. 4 is a sectional view on l ne 4-4 of Fig. 3, showing details of the drive means employed.

Fi 5 is a view similar to that of Fig. 3,

"but s owing a'second form of drive means.

Fig.6 is a sectional view on line 66 of Fig. 5, showing details of a second form of drive means. A v v In order that the advantages of aplplicants construction can be readily rea 'zed a short description of the usual form of this type of device follows:

Pum s of this character are usually constitute (see Fig. 1) by a cylindrical body or stator'S, within which rotates-a cylindrical drum or rotor R, the axis of the rotor is parallel to that of the stator but is positioned eccentric thereto by an amount it whereby the rotor contacts with the inner surface of the stator, at the point A. A plurality of blades P is positioned in slots 1' formed in the rotor.

A device constructed as described just above operates in the following manner. If it be assumed that the rotor moves in the direction cf the arrow 7', it will be seen that .passing from the point of tangency A, the

volume of the compartment mcluded be tween two consecutive blades increases constantly throughout a travel of 180. volume becomes a maximum when the com- This.

partment under consideration reaches the point B. The compartments which are thus at the inlet condition communicate with the inlet conduit C.

On the contrary, during the second half revolution the volume of each compartment constantly decreases until it becomes amini- 'mum once more at the point of tangency A.

These decreased sized compartments communicate with an outlet conduit D and thus fluid is forced out through the conduit 1)..

In such an apparatus the displacement of the blades P in an outward direction and the application thereof against theinner surface of the stator S, is producedby the action of centrifugal force which comes into play due to the rotation of the rotor.-

These devices are very simple in construction and thus from this point of view are very desirable, but at the same time they have two principal defects as set forth in the following:

In the first place the displacement of the blades in an outward direction is produced by the action of centrifugal force and hence such displacement does'not take place until after a certain speed of rotation is'attained.- Below this speed the blades do not aiford a tight contact with the inner surface of the stator and thus the pump does not function at these lower speeds.

A second "defect in such devices is due to the fact that the'pressure of the blades on the inner surface of the stator, which is due to the action. of centrifu a1 force, increases.

according to the square 0 the speed of rotation and thus rapidly reaches a very high value. As a result considerable friction is created between the blades and the stator and this very materially decreases the out-- overcomes the above set forth defects. In order to clearly show the advantages of the new construction the above description of the usual form of construction is quite essen- 6 tial.

A. device according to the present invention comprises a rotor 1, the axis of which is parallel to the axis of a stator 2 but which is eccentric thereto so as to be tangent to the stator along a stator eneratrix at 3. The rotor is formed of a p urality of like sectors 4, each connected by screws or the like 5 at each end, to plates 7 which plates carry hollow cylindrical axles 8 of large diameter, mounted on roller bearings 9 so as to rotatably support the rotor.

Each sector 4 of the rotor is spaced from the adjacent sector by a distance permitting a blade 10 to slide therebetween. Each of these blades 10, which are the propelling blades of the pump, is pivotally carried by a suitable system of pivoting means, to a tubular shaft 11 the axis of which coincides with the general axis MN of the stator.

The blades are formed from rectangular sheets of steel or other suitable material and are each attached at three points, as shown in Fig. 3, to three sleeves 12 which are carried by, and can readily turn with but slight friction on the axle 11. The blades are fastened by means of rivets, for example, between the arms 15 carried by the sleeves 12 (Figs. 2 and 3) The shaft 11 passes through the hollow cylindrical axles 8 of the rotor and is supported on ball bearings 16.

With the above described construction the blades 10 consequently turn about the general axis MN of the stator, and being carried by the axle 11 they cannot separate therefrom due to centrifugal force. Thus the bearing of the blades against the stator can be adjusted to the proper amount and does not depend on, or vary during, the operation of the device.

It will, therefore, be possible to adjust the outer edge of the blades relative to the stator so that there will be no leakage therebetween without fear of causing undue friction which' would result in harm to th blades and .to the stator.

It is to be noted that as a result of centrifugal force the blades press their sleeves 12 against the axle 11 and thus carry the axle 11 around with them in their rotation so that but little wear is caused between the axle 11 and the sleeves 12.

There is, however, a slight relative motion necessar between the axle 11 and the sleeves, ue to the eccentric mountin' of the rotor relative to the stator, as can e seen from the angular variation between the blades and the rotor (Fig. 2). This relative motion between the axle and the sleeves 14, is during each half revolution determined by the angle 17, Fig. 2, which due to the small diameter of theaxle 11 is of little relative importance.

It is very evident that the arrangement of these various details of construction could be .considerably modified without thereby changing the principle of the invention. In particular it would be possible to have a tubing rotatably carrying the blades and journalled on the shaft fixed on the case.

As already noted above, as a result of the eccentricity of mounting, although the sectors constituting the rotor are equal to each other, the angles Which the blades make with the sector through the rotation, are not equal. This angle is a maximum when the blade under consideration is at the point B, Fig. 1, that is at the end of admission. On the other hand this angle is a minimum when such blade reaches the point of A which is the end of the exhaust position. This condition of change of angularity of the blades with respect to the rotor segment, producing an increased out flow volumeand increases the pressure which the device is capable of giving.

A difiiculty is now encountered in rotatipg the rotor at an angular speed equal at times to the drive axle.

It would be possible to rotate the rotorby means of the axle 11. which carries the blades, by making use, for example, of a drive blade which would be fixed to the axle 11, but in this case the rotation would not be regular. ,In such a case the angular speed of rotation would be a maximum at A and a minimum at B.

This would have the effect of causing inertia effects and vibrations which are always prejudicial to the operation of such devices. Also the drivin blade which would, have to do a very considerable amount of work would rapidly become worn out.

It is, therefore, preferable to directly drive the rotor so that the rotor can then cause the angular displacement of the blades. This displacement of the blades relative to the' rotor is very small, the angle17, and since the blades are very light and are supported by the axle 11 the inertia efi'ects set up will be quite negligible and no harmful vibration produced.

The actual structural arrangement adapted is the following. One of the axles 8 Fig.

3 is furnished with a gear 18 which meshes by two ball bearings 21. It is to be noted that since the gear 19 is of greater diameter than the gear 18 of the rotor, the latter will turn faster than the former and this will readily permit of reducing the dimensions of the pump or compressor.

Fig. 5 shows a second form of drive wherein the drive shaft is parallel to the general axis MN of the device, but where the drive is effected by exterior gears. The gear 18 in this case meshes with a gear 22 fixed to a drive shaft 23 which is supported by two ball bearings 24. The axle 11 in the case is supported by two ball bearings 25 which rest directly in the casing of the pump. 0

Having described my invention, I now claim:

A rotary pump, comprising, a stator with an inlet and an outlet, a rotor positioned within, and eccentric to, the stator, propeller blades rotatably carried by the rotor and non-movable thereto in a radial direction, a gear at one end of the rotor, a drive shaft, coaxial with the stator, and a gear on the drive shaft in mesh with the rotor gear, the rotor comprising, a plurality of like sectors held in spaced relatlonship, the blades projecting through the spaces between the sectors and bearing in a fluid tight manner against the inner surface of the stator, an axle journalled at each end in, and concentric with, the stator, separate collars snugly but rotatably carried by the axle, the blades being each fixed to separate ones of the 1 collars.

In testimony whereof I have signed my name to this specification.-

mam: JEAN PAUL EMILE coznrrr. 

